Field of the Invention
The present invention relates to an audiovisual access criterion updating method, an updating code generating system, an updating code generating device, an audiovisual access criterion managing device, a content receiving system, and a content distribution system.
Description of the Prior Art
It is a current trend to distribute content signals from broadcast stations and then play the content signals with an electronic machine, such as a smartphone, a personal computer, and a TV set. Content signals are encoded and distributed so as to protect distribution-related interests of a content distributor engaged in a paid broadcast service. In this regard, only those users which entered into a contract with the content distributor can decode the content signals and thereby watch and listen to the contents. An audiovisual access criterion has to be updated whenever a user wants to extend an audiovisual access deadline for the content or wants to watch and listen to content from another content distributor.
Citation 1 discloses a method of initializing an audiovisual access deadline but does not mention updating the audiovisual access deadline. Citation 2 discloses a method of setting a validity deadline by a broadcast wave but has a drawback: the validity deadline cannot be set, unless the broadcast wave carries validity deadline information.